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FOSSILS

Make Plaster Fossil Casts

Safety Rules:
Parent supervision
Take care with Plaster of Paris (It is poisonous)
 
Materials you need are:
Plaster of Paris (from the pharmacy)
an old container for stirring (e.g. an icecream container)
an old tray with deep sides
an old spoon
some water
a jug for the water
some objects that would make interesting fossils (e.g. shells)

Put all of the Plaster of Paris into the old container and add small dribbles of water a bit at a time (Don't add too much or it will become too runny). As soon as you have a mixture that is a stiff paste consistency, spoon it into a tray and put in your objects to be fossilised. (Be quick because some Plaster of Paris contains additives that speed up the setting process. Some can harden within 15 minutes!) When the plaster starts to harden, pull out the objects and wash off the plaster thoroughly. (Remember that the hardened plaster is extremely difficult to wash off so wash your containers immediately after use with a lot of water.)

Make Plaster Fossil Moulds

Safety Rules:
Parent supervision
Take care with Plaster of Paris (It is poisonous)
 
Materials you need are:
Plaster of Paris (from the pharmacy)
some clay or plasticine
an old container for stirring (e.g. an icecream container)
an old spoon
some water
a jug for the water
some objects that would make interesting fossils (e.g. shells)

Make an impression in the clay or plasticine with your 'fossil'. Put some of the Plaster of Paris into the old container and add small dribbles of water a bit at a time (Don't add too much or it will become too runny). As soon as you have a mixture that is a stiff paste consistency, spoon it into the impressions made by your 'fossils' (Be quick because some Plaster of Paris contains additives that speed up the setting process. Some can harden within 15 minutes!) When the plaster hardens, take it out of the clay or plasticine.